Node.js 24 Powers the Next Generation of AWS Lambda Serverless Apps

Developers eager to leverage the latest in serverless technology can now deploy their AWS Lambda functions using Node.js 24. This upgrade brings a robust, production-ready runtime with active LTS support through April 2028, ensuring both stability and access to modern JavaScript features.

What’s New in the Node.js 24 Lambda Runtime?

• Modern Handler Support:
  Lambda now exclusively supports async/await and synchronous handler signatures. The days of callback-based handlers are over—legacy methods like context.succeed Copy, context.fail Copy, and context.done Copy have been removed. This streamlines error handling, aligns with current JavaScript standards, and encourages clearer, more maintainable code.
  
  
• Consistent Promise Handling:
  Both streaming and non-streaming Lambda functions now handle unresolved promises consistently. After your handler returns, Lambda will not implicitly await background asynchronous tasks. Developers must explicitly manage all async operations within the handler or streaming pipeline, ensuring precise control over execution flow.
  
  
• Experimental Feature Management:
  For stability, experimental Node.js features—such as ES module detection and using require() Copy in ESM—are disabled by default. If your application depends on these, you can enable them with the NODE_OPTIONS Copy environment variable, but note that AWS support and SLAs exclude related issues.
  
  
• Inline ES Modules for CloudFormation:
  Node.js 24 simplifies the use of ES module syntax for inline Lambda functions defined in CloudFormation, eliminating extra packaging steps for small serverless utilities and accelerating development workflows.

Key Node.js 24 Language Enhancements

• Undici 7 HTTP Client:
  This update offers improved network performance, especially for Lambda functions with heavy HTTP workloads. Features like enhanced connection management and HTTP/2 support are now available out of the box.
  
  
• Explicit Resource Management:
  With the new using Copy and await using Copy syntax, developers can deterministically manage resource cleanup, reducing the risk of leaks and boosting invocation efficiency.
  
  
• AsyncLocalStorage Improvements:
  Defaulting to AsyncContextFrame Copy improves the reliability and performance of context propagation. This is particularly valuable for logging, tracing, and handling request-scoped data in serverless patterns.

Performance and Migration Notes

• Initial Cold Start Times:
  While Node.js 24 may experience slightly longer cold starts initially due to lower usage, these times should improve as adoption increases. Developers are encouraged to benchmark and optimize workloads as needed.
  
  
• SDK and OS Updates:
  Lambda now includes AWS SDK for JavaScript v3 by default. Code using v2 must be upgraded to ensure compatibility. The runtime runs on Amazon Linux 2023, which replaces yum Copy with microdnf Copy; adjust Dockerfiles accordingly for container-based Lambda deployments.

How to Deploy Node.js 24 in Lambda

Select Node.js 24 as your runtime when creating or updating Lambda functions using the AWS Management Console, CLI, SDKs, AWS SAM, or CDK. For container images, update your Dockerfile to reference the Node.js 24 base image.

Conclusion

Node.js 24 on AWS Lambda is a major advancement for serverless JavaScript development. By adopting these updates, teams gain access to modern language features, improved consistency, and enhanced performance. This empowers developers to build more reliable, maintainable, and efficient serverless applications. For further examples and resources, explore the Serverless Patterns Collection and Serverless Land.

Source: AWS Compute Blog